The present invention is directed to an automatic cleaning device for use in an extracting furnace of an apparatus for analyzing gases, particularly nitrogen, oxygen, hydrogen and the like, contained in metals.
The present invention is more particularly directed to such an automatic cleaning device which is capable of saving manual labor required to clean an extracting furnace of the direct heating type in which a crucible containing a metal sample is held between upper and lower electrodes and resistance heated, whereby gases contained in a metal sample within the crucible are extracted and directed to a gas analyzing apparatus.
In the use of such systems, it is necessary to clean the interior of the extracting furnace after every gas analyzing operation because the inside surfaces of the extracting furnace become stained due to sudden boiling of the molten metal sample, sublimination of the crucible and the like. In the past, such cleaning has been carried out manually. However, manual cleaning is inherently inefficient, particularly when from 100 to 200 cleaning operations per day must be carried out. This is further particularly true, when the extracting furnace is normally located in an iron or steel plant wherein the environment is not conducive to thoroughly precise and repetitive cleaning operations. Additionally, there are likely to occur different qualities or degrees of cleaning of the interior of the extracting furnace due to different persons conducting cleaning operations. This results in different degrees of cleaning of electrode surfaces, thereby resulting in varying contact resistance between the crucible and electrodes. This alters the extraction efficiency, which can influence the results of the following analyses. Even further, soot-like dust is generated during the cleaning of the interior of the extraction furnace and such dust not only soils the apparatus but also the surrounding environment. This necessitates that the workers must wear masks.